Pop-up sprinklers are commonly used to provide water to lawns. The sprinklers are connected via risers to underground water piping. The sprinklers have cylindrical bodies which are embedded in the soil with an annular top even with the top of the soil. Mounted concentrically with the embedded body is a cylindrical element which, when activated by water pressure, pops up above the grass to provide a spray of water over an area of lawn. When the water is turned off, the element retracts such that the top of the pop-up element is recessed from the annular top of the cylindrical body. In general, a multiplicity of pop-up sprinklers are provided in any sprinkler system.
The grass comprising a lawn tends to grow more densely around the sprinkler heads because of the proximity to water. The dense growth periodically needs to be trimmed to guarantee even distribution of the spray.